Electronic devices such as smartphones, tablets, and computers can store a large amount of personal information about authorized users of such devices. In various examples, a smartphone may store the authorized user's credentials on email services, backup services, or Web sites. Electronic devices may also include the authorized user's personal phonebook and/or pictures of the authorized user's family members. To inhibit misuse of this personal information, such electronic devices generally lock after they are inactive for a certain amount of time. When locked, the information on the electronic device is inaccessible until unlocked, e.g., by entering a password or personal identification number (PIN).
Electronic devices are generally configured to lock after a fixed amount of time of nonuse. This may inconvenience the authorized user, who may be required to unlock an electronic device after only a brief period of attention to something other than the electronic device.